The prize for most interesting campaign contribution of the week once again goes to Democratic gubernatorial candidate and San Francisco Mayor Gavin Newsom.

Real estate investor Thomas J. Coates of San Francisco, a principal in Jackson Square Properties, on Tuesday gave Newsom’s campaign $25,000. Coates is a Republican who put up almost $1 million — $223,400 in contributions and $750,000 in loans — for last June’s Proposition 98, the ballot measure that would’ve phased out rent control in California and curtailed government’s right to seize private property by eminent domain.

I can’t immediately find any reference to where Newsom stood on Prop. 98, but among those who opposed it were Gov. Arnold Schwarzenegger, U.S. Sen. Dianne Feinstein, former Gov. Pete Wilson, the AARP, the League of California Cities, the California League of Conservation Voters, the California Teachers Association, the SEIU, the California Chamber of Commerce — and, ultimately, 62 percent of voters.

Two weeks ago, I was first to report that Newsom’s campaign had received $25,000 from Rockstar energy drink CEO Russell Weiner, who also is the son of right-wing radio host Michael Savage and a former Republican Assembly candidate; the campaign last week announced it would give that money back, claiming “the confusion caused by the conflicts between the views expressed by Mr. Weiner in his campaign for State Assembly and the views and values of Mayor Newsom are best adressed this way.”